This invention relates to pull starters for small engines and, more particularly, to mechanisms for transferring energy from the pull starter into a rotational force on a flywheel to thereby crank the engine.
Recoil starter or pull cords are generally used for cranking small engines, such as chain saws, trimmers, lawn mowers and the like. Usually, the starters include a handle secured to a cord, or lanyard, which is coiled around a pulley combined with a ratchet wheel rotatable thereby. The flywheel is generally provided with pivotable pawls adapted to engage and be driven by the ratchet wheel. When the operator pulls the starting lanyard, the pawl engages the teeth of the ratchet, causing rotation of the flywheel, thereby cranking the engine. Upon starting of the engine, the pawls will pivot, due to centrifugal force, out of engagement with the ratchet so that the starter will be uncoupled from the flywheel.
In the past, one structure for such a pawl assembly included a metallic stamping having, at one end, a foot portion for engagment with the ratchet and, at the opposite end, a spur to engage a vane of the flywheel. In addition, a constant force, coil spring served to provide a rotational force on the pawl and thus urged the pawl into engagement with the ratchet. Among the drawbacks to that structure was that, in order to rotatably mount the pawl to the flywheel, the pawl and coil spring has to be assembled together and a rivet, or ribbed pin, had to be fitted through the pawl and spring assembly and then hydraulically press-fitted into a bore in the flywheel which involved substantial labor costs during the assembly procedure.
Accordingly, the principal object of this invention is to provide a pawl and spring assembly adapted for ease of assembly onto a flywheel, without the need of tools, as was required for conventional pawl assemblies adapted to be press-fitted onto the flywheel.